1. Field of the Invention
The present invention relates to an air flap arrangement for a motor vehicle comprising a housing having an air passage opening, at least two air flaps movably mounted on the housing and a force- and motion-transmitting motion drive coupled to the air flaps, wherein the at least two air flaps are coupled by a transmission and/or linkage for mutual movement, and wherein the at least two air flaps are movable between a closed position, in which closed position the cross-sectional area of the air passage opening through which air can flow is reduced, and a passage position, which is different from the closed position, and in which passage position the cross-sectional area of the air passage opening through which air can flow is greater than in the closed position.
2. Background of the Related Art
Such air flap arrangements are generally known in the automotive industry. They are generally used in motor vehicles to supply the engine compartment positioned behind the air flap arrangement in the direction of flow of the air passage opening with cooling air for convection cooling as needed.
Air flap arrangements are relevant to emissions, since reducing the size of or closing the air passage opening upon a cold start can withdraw the cooling air from the internal combustion engine and, if desired, from its surrounding assemblies, which can result in a faster warm-up of the internal combustion engine to the nominal operating temperature with accordingly optimal combustion. Thus, the use of the above-described air flap arrangements can shorten cold-start phases with disadvantageously high levels of pollutant emission.
The closed position can advantageously be a position in which the air passage opening is completely blocked for the passage of air. This then means that the cross-sectional area of the air passage opening is reduced to zero. The cross-sectional area should always be orthogonal to the direction of flow, which can vary depending on the relative position of the air flaps with respect to the housing.
The through-flow cross-sectional area of the air passage opening is preferentially at a maximum in the passage position.
To simplify the construction of the known air flap arrangement, the motion drive is usually directly coupled in a force- and motion-transmitting manner to one of the air flaps or to a drive and/or linkage part and is directly coupled via the designated transmission and/or linkage to the other air flap, such that all air flaps coupled by the transmission and/or linkage for mutual movement are synchronously drivable for the relative movement by the motion drive relative to the housing movably supporting them. As a rule, preferably all of the at least two air flaps therefore have the same relative position relative to the housing movably supporting them at any time.
Owing to the provided motion coupling of the air flaps for mutual movement with each other, only the actuator is frequently checked for functionality, for instance by the on-board computer of a motor vehicle carrying the air flap arrangement. If the actuator in the off-board information network of a motor vehicle is recognized as functional, then the whole air flap arrangement is assumed to be functional because of the customarily robust construction of the air flap arrangement.
This conclusion can, however, possibly be misleading if, for example, a part of the motion coupling—that is to say of the transmission and/or of the linkage—of the air flaps is broken or if, for example, the direct coupling of the motion drive is defective with regard to one air flap or one transmission and/or linkage part.
Numerous diagnostic processes in motor vehicles are known in the prior art, mostly designated with the acronym “OBD” (onboard diagnosis). On-board diagnosis is of increasing importance precisely for emissions-relevant components of motor vehicles. In this connection, DE 101 55 647 B4 discloses an on-board diagnostic process having weighted classes of a classification memory in order to realize a condition statement about a component to be checked that is as accurate as possible.
The OBD processes and devices, however, generally relate to the operation of the internal combustion engine and to the exhaust emission quality (see, for example, U.S. Pat. No. 6,225,898 B1 or U.S. Pat. No. 7,938,105 B2 or EP 1 606 503 B1).